(1) Field of the Invention
The present invention relates to a water-filter device having an adjusting mechanism for setting a mixing ratio, and to a water tank which is provided for accommodating the filter device, to an appliance with a water tank, and to a filter appliance having a water filter device with one or more sections for treating water, in particular by ion exchange and having an adjusting mechanism for setting a mixing ratio between water treated by the filter section and water which is guided past the filter section via a bypass section and is not treated or is treated some other way that is characterized by the provision of an adjusting mechanism of which the volume and/or structure change/changes by way of a liquid which is in contact with the adjusting mechanism and/or has flowed through the adjusting mechanism as well as water tanks having an insertable filter cartridge which accommodates the foregoing water filter device, appliances with a water tank having the foregoing water filter device and filter appliances having a filter head with the foregoing water filter device.
(2) Description of Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
Filter devices for treating a liquid and having a mixing device for the admixture of liquid which is not treated, or has been treated elsewhere, to the liquid treated in the filter section have been known for some time now, in some cases with a possible means of adjusting the mixing device. As far as the treatment goes, the liquid is treated chemically and/or physically, for example water is softened, dealkalized, demineralized or the like.
Essentially two types of filter devices have been established. A first type of filter device is constituted by line-dependent, pressurized filter systems, e.g. so-called “filter candles”, which can be integrated in the supply line of a water-discharge point or water-discharge device, preferably in the form of an interchangeable unit.
On the other hand, in addition to these filter candles, so-called “filter cartridges”, in the form of line-independent filter devices, have proven expedient, usually in conjunction with a corresponding mater tank.
The mixing devices mentioned in the introduction are provided for setting a water quality which is predetermined for the respective application, in order for water treated via a filter section to be mixed with water which is not treated or is directed via a further filter section.
Such systems are used, for example, as a central or decentralized installation for treating drinking water in private households, for supplying discharge points, specifically for supplying modern kitchen appliances (water faucets and icemakers in modern refrigerators or coffee machines) and also in the commercial sector for supplying drinks machines for preparing coffee, steam, hot or cold water for optimizing the taste of the food and drinks treated or prepared therewith and for protecting the machines against water-induced technical problems.
The mixing arrangements which have been customary until now in the application area described are set at the beginning of operation, by means of an adjusting mechanism for controlling a liquid stream, to a predetermined mixing ratio which is determined from the mineral content and/or hardness content of the input water, this content being known or determined by a short test, and from the quality of the filtrate water required for the application.
The output of the various treatment stages, however, becomes gradually depleted in dependence on the quantity of water already channeled via the treatment section and on the quality of the untreated water, so that, in the case of a mixing ratio fixed by means of an adjusting mechanism for controlling a liquid stream, the water quality produced changes continuously in dependence on the degree to which the treatment section has become depleted.